BIOC Module 4

To oxidize the fatty acids in a triacylglycerol, what must occur first?
lipolysis
fatty acid activation
transport into the mitochondria
oxidation of a carbon-carbon single bond to an alkene
reduction of a carbon-carbon double bond
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Terms in this set (33)
To oxidize the fatty acids in a triacylglycerol, what must occur first?
lipolysis
fatty acid activation
transport into the mitochondria
oxidation of a carbon-carbon single bond to an alkene
reduction of a carbon-carbon double bond
lipolysis
What transport system moves activated fatty acids from the cytosol to the mitochondrial matrix?
triacylglycerol shuttle
glycerol phosphate shuttle
carnitine shuttle
acyl adenylate shuttle
lipoprotein shuttle
carnitine shuttle
In the b-oxidation pathway, the oxidation occurs at carbon _____ with the acetyl group that becomes acetyl-CoA derived from the _____ end of the fatty acid.
3; methyl
1; carbonyl
3; carbonyl
1; methyl
2; carbonyl
2; methyl
3; carbonyl
The activation of acetyl-CoA for fatty acid synthesis is achieved by converting the acetyl-CoA into _____.
propionyl-CoA
acetoacetyl-CoA
HMG-CoA
b-hydroxybutyryl-CoA
malonyl-CoA
malonyl-CoA
In the process of nitrification, nitrite reductase converts _____ into _____.
nitrate; nitrite
nitrate; nitrogen
nitrite; nitric oxide
nitrite; ammonia
nitrogen; nitrite
nitrite; ammonia
Which of the following citric acid cycle intermediates can be converted to aspartate via transamination?
oxaloacetate
succinate
fumarate
a-ketoglutarate
citrate
oxaloacetate
Which of the following amino acids is properly paired with the amino acid from which it is derived?
Gln: Asp
Pro: Ala
Arg: Lys
Tyr: Phe
Gly; Val
Tyr: Phe
What enzyme catalyzes the conversion of phenylalanine to tyrosine
phenylalanine hydrolase
phenylalanine desaturase
phenylalanine hydroxylase
phenylalanine oxidase
phenylalanine decarboxylase
phenylalanine hydroxylase
Which of the following amino acids is a source of both carbon and nitrogen for IMP synthesis?
Glu
Gly
Gln
Asp
Asn
Gly
The energy for the conversion of IMP to GMP is supplied by _____.
CTP
GTP
TTP
UTP
ATP
ATP
What nucleotide is methylated to produce dTMP? dUMP dAMP dCMP dGMP both dCMP and dUMP can be converted to dTMPdUMPWhich of the following correctly describes the general synthesis of purine nucleotides? The basic ring structure, orotate, is synthesized and then linked to PRPP. The basic ring structure, orotate, is synthesized stepwise on PRPP. The basic ring structure, hypoxanthine, is synthesized stepwise on PRPP. The basic ring structure, hypoxanthine, is synthesized and then linked to PRPP. The basic ring structure, hypoxanthine, is synthesized and then linked to ribose-5-phosphate.The basic ring structure, hypoxanthine, is synthesized stepwise on PRPP.Which of the following statements is correct about cAMP and signal transduction pathways? The hormone stimulus leads to increased amounts of adenylate cyclase. The hormone-receptor complex enters the cell and activates the adenylate cyclase. cAMP acts to dissociate the hormone from the hormone-receptor complex. cAMP modulates the activity of specific protein kinases. cAMP promotes the degradation of adenylate cyclase.cAMP modulates the activity of specific protein kinases.The second messenger _____ opens Ca2+ channels in the cytoplasmic membrane. inositol trisphosphate diacylglycerol cAMP cGMP nitric oxidecAMPActivity of the Ras protein is analogous to the _____ in terms of its ability to bind GTP. G protein beta subunit G protein alpha subunit G protein gamma subunit G protein-coupled receptor G protein beta-gamma dimerG protein alpha subunitInsulin binds to a receptor that ______. is coupled to a G protein. possesses serine/threonine phosphatase activity. migrates to the nucleus to affect gene transcription. possesses tyrosine kinase activity. directly activates MAP kinase.possesses tyrosine kinase activity.In a variation of the Cori cycle, what amino acid is transported from the muscle to the liver? alanine glycine glutamate aspartate glutaminealanineWhich of the following best explains the chain of events that occurs when glucagon binds to its receptor? activation of protein kinase A, activation of G protein, activation of adenylate cyclase, production of cAMP activation of adenylate cyclase, production of cAMP, activation of protein kinase A, activation of G protein production of cAMP, activation of adenylate cyclase, activation of protein kinase A, activation of G protein activation of G protein, activation of protein kinase A, activation of adenylate cyclase, production of cAMP activation of G protein, activation of adenylate cyclase, production of cAMP, activation of protein kinase Aactivation of G protein, activation of adenylate cyclase, production of cAMP, activation of protein kinase AAfter several days of fasting, the liver begins producing relatively large amounts of ketone bodies. Which type of tissue is highly dependent upon this as its sole source of energy in the absence of glucose? heart kidney skeletal muscle brain adipose tissueWhich compound links glycolysis, nucleotide synthesis, and glycogen synthesis? Glucose-6-phosphate Glucose-3-phosphate Acetyl-CoA Oxaloacetate CitrateGlucose-6-phosphateWhich coenzyme is the source of reducing power for the synthesis of fatty acids?NADPHKetogenic amino acids are catabolized to which compound?acetyl coA or acetoacetateThis molecule reacts with long chain fatty acids for transport across the inner mitochondrial membrane.carnitineWhich amino acid is an intermediate in the urea cycle?ArginineIf a reaction that included all of the enzymes involved in fatty acid synthesis was supplied with excess ATP, NADPH, acetyl-CoA and 14CO2 (where the carbon was a 14C-label), where would the labeled carbon appear in the finished fatty acid? A. odd-numbered carbons B. even-numbered carbons C. every third carbon D. every fifth carbon E. no carbons would be labeledno carbons would be labeledThe conversion of 3-hydroxybutyrate to two molecules of acetyl-CoA produces 1 NADH and consumes 1 equivalent of ATP. What is the net ATP yield from the complete oxidation of 3-hydroxybutyrate in a eukaryotic cell? A. 1.5 B. 11.5 C. 13.5 D. 21.5 E. 23.521.5Glutamate undergoes a(n) _____, catalyzed by glutamate dehydrogenase, to yield a-ketoglutarate, NADH and _____. A. reductive deamination; water B. oxidative deamination; ammonia C. reductive amination; water D. oxidative amination; ammonia E. none of the aboveoxidative deamination; ammoniaWhich of the following statements about nucleotide metabolism is false? A. The methyl group donor for dTMP synthesis is N5N10-methylene- tetrahydrofolate. B. Pyrimidine nucleotide synthesis begins with ribose 5'-phosphate, whereas in purine nucleotide synthesis the sugar molecule is added later in the pathway. C. Ribonucleotide reductase catalyzes the conversion of ribonucleotides to deoxyribonucleotides. D. Inosine 5'-monophosphate (IMP) is the precursor for synthesis of AMP and GMP. E. Nucleotides can be synthesized from the corresponding bases in a single reaction via the salvage pathways.Pyrimidine nucleotide synthesis begins with ribose 5'-phosphate, whereas in purine nucleotide synthesis the sugar molecule is added later in the pathway.For the receptor tyrosine kinases, what specific type of secondary structure predominates in the transmembrane domain of the receptor?alpha helixIn most signal transduction pathways, what functional group is added or removed from proteins to activate or inactivate activity?phosphateThymidylate synthase catalyzes the addition of what chemical group to dUMP?methylIn purine nucleotide catabolism, what end product is excreted in the urine in mammals?uric acid (urate)Signal transduction pathways are central to the regulation of cellular processes. Which of the following statements is not true of signal transduction pathways? A. Signal transduction pathways typically involve the activation of protein kinases and protein phosphatases. B. Intracellular second messenger molecules include cGMP, calcium ions and inositol trisphosphate. C. When a hormone binds to a G-protein-coupled receptor, a conformational change in the receptor activates the associated GTP-binding protein. D. 7-transmembrane segment (7-TMS) receptors typically have a tyrosine kinase activity. E. A receptor protein has an extracellular domain that is responsible for interacting with a specific ligand such as a hormone.7-transmembrane segment (7-TMS) receptors typically have a tyrosine kinase activity.